Priming mixture.



UNITED STATES T x men.

HENRY C. PRITHAM, OF BRIDGEPORT, CONNECTICUT, ASSICNOR TO THE UNION METALLIC CARTRIDGE COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORA- TION OF CONNECTICUT.

No Drawing.

To all whom it may concern:

Be it known that 'I, HENRY C. PRITHAM, a citizen of the United States, residing at Bridgeport, county of Fairfield, State of Connecticut, have invented an Improvemerit in Priming Mixtures, of which the following is a specification.

This invention relates to priming mixtures generally; that is, mixtures adapted to be pressed into primers for center fire ammunition or into the rims of cartridge shell heads for rim fire ammunition for the purpose of igniting powder charges when exploded or detonated by a sharpblow.

Priming mixtures must be composed of at least two compounds, one of which must contain oxygen in a condition for easy liberation, the other must bea compound con.- taining an element or elements that will combine very readily with the oxygen and thus produce combustion. Various substances may be used to produce this result and the mixture may contain a plurality of substances or compounds carrying oxygen and a plurality of elements, substances, or

compounds that will combine with the oxygen. All priming mixtures must be abso-' lutely stable at ordinary temperatures and under ordinary conditions, but when heat is generated in them by friction from a sharp blow they must burn exceedingly fast, 2'. e., explode, detonate. It will be understood of course that different powders require more or less quick burning priming mixtures and more or less flame and the desired results are secured by varying the ingredients and the proportions of the ingredients in the mixture. It is sufiicient for the purposes of this specification to mention as well known compounds carrying oxygen and used in the manufacture of priming mixtures, mercuric fulminate, potassium chlorate and barium peroxid, and as elements or compounds that will combine easily with oxygen, carbon, sulfur, sulfids of the metals, sulfocyanids of the metals and carbohydrates. These various mixtures, whether fulminate or non-mercuric, are retained inprimers orin the rims of cartridge heads by the use of various gums, as shellac, gum 'arab c or tragacanth, or by the use of colledion'.

As all of thesemixtures are in amore 'or less.

loose condition and are held by the'guin, it follows that they. yield more or-less when the primer or cartridge head 1s struckbya Specification of Letters Patent.

PRIMING MIX-TUBE.

Patented Dec. 2* 1912.

Application filed June 27, 1912. Serial No. 706,262.

firing pin or hammer. There is a local explosion at the point of impact, the heat of whlch is of course at once transmitted to the restof the mixture, but it takes a minute fraction of a second and if the mixture requlres a heavy blow, it often happens that a piece of the mixture is knocked away from the primer or head and does not ignite the mixture.

I have discovered by repeated experiments that by combining Withthe mixture while in a, plastic condition any self-hardening mineral cement it will serve as a binder and cause the mixture to set to a hard solid mass, the various mixtures will remain hard when exposed to the air; that the mixture will not shrink and break away from a primer or cartridge ,head, but will remain firmly in place, without the use of gums or varnish of cement required will, of course, vary with the conditions of use, as, the kind of cement used or the composition of the priming mixture. I find that with Portland cement, from two to four ,per cent. of the total Weight of the mixture is all that is needed, the variations within these limits depending on the composition of the priming mixture. With an oxychlorid cement, as, magnesium oxychlorid, consisting of two parts oxid of magnesium and one part of a chlorid of the alkaline metals, from one and one-half tov four and one-half per cent. of

the total Weight of the mixture may be used, depending, as stated above, on the various log conditionsof use. A very satisfactory result with a non-mercuric priming mixture is secured by the use of approximately three'ios per cent. of magnesium oxychlorid cement.

The proportion-of cement may in all cases. be varied within the limits stated to suit the" priming mixture. z

' The cements may be added n component parts to the prim ng mixture or may be V. B. STILL. MUFFLER. APPLICATION FILED APR.4. 1912 Patented Dec. 24, 1912.

2 SHEETSSHEET 1.

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